This invention relates generally to a plating evaporative recovery tank, and more particularly to a plating evaporative recovery tank which includes a removable blower sleeve.
As is well known in the art, various problems and difficulties are encountered in providing suitable means for evaporating water from a solution to the atmosphere. This is especially true with respect to solutions provided in electroplating processes wherein large amounts of rinse water are required. Electroplating processes require thorough rinsing of the workpiece between the various steps of pretreatment as well as during plating and after plating.
Numerous rinses are commonly employed to prevent contamination of subsequent operations by diluting the chemical films left on a workpiece by previous immersions. These rinses generally consist of tanks full of tap water that are continually overflowed by additional water wherein the "rinsing ratio" of each rinse can be calculated. In one process known as "counter-flow rinsing", there are provided several in-line tanks which define rinse stations. This type of process saves water by multiplying the dilution effect with the use of several rinse stations.
However, if the rinse tanks are not properly arranged to cooperate with an efficiently designed atmospheric evaporator, drag-out from the plating tanks becomes wasteful and expensive. The only reason for rinsing is to remove the plating chemicals from the surface of a workpiece. These chemicals are then generally flushed down the drain or sent to waste treatment.
Hence, some types of operations become too expensive due to several factors: the loss of drag-out, the treatment of the effluent to the satisfaction of the Regulatory Agency, and the cost of large amounts of water required and the associated sewer charge.
One of the more efficient recovery systems includes the counter flow of the rinse water and drag-out through several rinses to the process tank. The excess water is removed from the process solution by the evaporative tank, with the heat for evaporation being taken from the process tank. Accordingly, the atmospheric evaporator depends on wet surfaces, forced air, and the available heat taken from the solution for evaporation.
Other drag-out recovery systems employed by some platers include drag-out concentration by boiling the rinse water, reverse osmosis, and the use of ion-exchange columns to collect various components of the plating solution from the rinse water.